By Jennifer Green

Scientists working at the SLAC National Accelerator Laboratory in California announced last week that an X-ray analysis has revealed a chemical connection between birds and dinosaurs.

Placing a 150 million year old Archaeopteryx specimen labelled ‘Thermopolis’ under a bright X-ray beam, the researchers discovered that the ‘dinobird’s’ chemical remains lay hidden just below the surface of the fossil.

By analysing how hair-thin X-ray beams interacted with the fossil, then comparing it to the composition of the surrounding rock, the scientists found significantly different concentrations of several elements, proving that they belong to the animal itself.

“People have never used a technique this sensitive on Archaeopteryx before,” said SLAC physicist Uwe Bergmann, who led the study. “Because the beam is so bright, we were able to see the teeniest chemical traces that nobody thought were there.”

From this they mapped the chemical composition of Thermopolis, which was published last week in the Proceedings of National Academy of Science. The results revealed that sections of the feathers are actually real fossilised material rather than mere impressions and contain phosphorous and sulphur – chemicals that are present in modern day birds.

“We talk about the physical link between birds and dinosaurs, and now we have found a chemical link between them,” said University of Manchester geochemist Roy Wogelius, corresponding author on the paper.

“In the fields of paleontology and geology, people have studied bones for decades. But this whole idea of the preservation of trace metals and the chemical remains of soft tissue is quite exciting.”

All ten Archaeopteryx specimens that have been discovered have undergone numerous different visual analyses and scans in the past, none of which revealed the hidden dinobird’s chemical remains.

“You would think after 150 years of study, we’d know everything we need to know about this animal,” said University of Manchester paleontologist Phil Manning. “But guess what - we were wrong.”

The new technique also provides an alternative method of analysing other fossil remains, potentially revealing new information about animals that have been extinct for a very long time.

“We’re able to read so much more into these organisms now using this technology - we’re literally touching ghosts,” said Wogelius. “Chemistry is the real key in the future of paleontology. It’s a paradigm shift.”

But the method does have its limitations. Only remains that have not been removed from their surrounding rock can be analysed this way because it is necessary to establish that elements belong to a specimen and have not been transferred from foreign sources.